Calculating apparatus for price and volume indicators



cATORs March 12, 1963 R. H. LlvEsAY cALcupATING APPARATUS FOR PRICE AND voLME: INDI Filed March 18. 1958 3 Sheets-Sheet 1 A LA ATTORN EYS March 12, 1963 R. H. LlvEsAY 3,081,031

ALcULATING APPARATUS FoR PRICE AND VOLUME: INDICATORS Filed March 18, 195e s sheets-sheet 2 DWI Ll .I IA.

ATTORNEYS R. H. LIVESAY March 12, 1963 CALCULA'IING APPARATUS FOR PRICE AND VOLUME INDICATORS Filed March 18, 1958 5 Sheets-Sheet 3 BROBERT H. LIVESAY ATTOR N EYS vintegration of products may also be provided.

the prices of -unit volumes. Anections involved require, practically, th-at vgasoline stations.

Vmodified with considerable. savings witched to the delivery stations.

-tion or integration of the yvention tothe dispensing This invention relates to calculating apparatus particularly adapted for effecting multiplication, division, evaluation of summations of multiplied quantities, evaluation of integrals, etc.

The present invention particularly relates to calculating apparatus in which pulses are-counted in a fashion which, though statistical in nature, will give rise to results `which may-be made as accurate as desired. It maybe generally characterized hy a statement that it involves'a source of pulsesfrouted to a plurality of channels with selection in the several channels of particular fractions 'of the pulses therein with accumulation of the pulses so resulting. The adoption of this procedure results in effective multiplication in various ways which will be hereafter described, and further extensions of the system are adapted for use in effecting division. Summation and In particular, the procedure lends itself to simplicity of decimal representations such as are usually most desirable.

In one` of its simplest forms, the invention is applicable tothe computations of prices of fuels delivered to vehicle tanks, effecting in simple fashion the multiplication of volume delivered by unit volume price. At the present "time, gasolinestationsare provided with the conventional pumps which involve metersproviding inputs to mechanical variatore involving complex gearing and set for The mechanical interconthe pumps shouldbe located'adjacent to the vehicles being serviced, andthis results in the conventional physical lay-out of In accordance with the present invention, the layout of such stations may be advantageously in space by providing relatively simple ovehead vhose delivery arrangements lwith remotey computation of prices which may be exhibited on conveniently located boards. For a` given number of delivery hose and nozzle arrangements, there lmaybe provided-'aconsiderably less number of calculating ork computing devices which may be selectively As .a result, the entire station equipmentmay bemade much less expensive.

As will appear, the invention is of much more general `applicability and may be used, for example, for effecting continuousmultiplication of two variables with summaproducts over particular periods.

Thevarious objects of the invention relate generally Vto the foregoing and tovarious detailsoftapparatus and 4operation which will become more apparent froml the followingdescription, read in conjunction with the accompanying drawings, in which:

FLGURE l isla diagram showing an embodiment of the invention particularly adapted to the `multiplication -of a variable quantity withan adjusted fixed quantity, the diagram being illustrative of the application ofthe inand pricing of fuel;

FIGURE 2 is a-diagram illustrating afurther embodiment. of the invention.particularly` adapted forV the continuous multiplication of two variable quantities to providesummation or integration, they diagram also showing Vthefashion inwhich the -.inventionfis adapted. to receive inputs from analog devices and provide an analog out- .run

atheuutimate exhibition of a 'the indicating devices ldidi Patented Mar. 12, 1963 reference to FIGURE invention adapted to the type of multiplication involved in calculation of the price of a -delivered fuel. Following description of FIGURE I there will then be discussed theA theory of operation involved.

There is indicated at 2 a fuel line leading to Ia delivery nozzle bywhich the fuel may be introduced-into a ve*- hicle tank. The line 2 includes a conventional volumetric meter 4 which is provided with an output shaft the rotations of-which correspond to the quantity of fuel delivered. The output shaft drives a pulsegenerator 6 to provide electrical pulses corresponding in number to the quantity of fuel measured by the meter. To cite-'a typical `figure, the pulse generator may produce onethousand pulses per gallon. The pulse generator may take numerous forms and is illustrated as involving a slotted disc 8 driven by the meter output shaft arranged to interrupt a beam of light passing from a lamp 10 to a photocell 12 -which is connected to an amplifier 14. -As

will be obvious, there might be here used for pulse generation a magnetized disc having pulse locations thereon associated with a magnetic pickup, mechanical interrupter means, or the like. The amplifier 14 may be provided with conventional means to provide at its output properly shaped pulses.

The output pulsesV are delivered to a first stage ring counter 16 which is followed by a series of similar ring counters at 13,20, 22 and 24. These ring counters are here merely diagrammed since they may take numerous well known forms. They may, for example, consist of conventional series of binary units provided by thermionic tubes, they may becounters of transistor type, or, in a quite simple form, they may consist of gas filled tubes having electrodes arranged in a circular'series to provide, upon the reception of pulses, stepping about of the'fired conditions of the electrodes as in the well-known Decatrom In the'case of each of these counters, the final stage is coupled back to the iirst stage so that the digit count is repetitive. Though not indicated in the figure, it will be understood that these counters have conventional zeroizing means associated therewith so that at thev beginning of each period of operation their counts may start from zero. Such ring counters are also provided with outputs designed to deliver pulsesupon the reaching ofseach new count, and such connections are illustrated for the first three ring counter stages at 26, 23 and 3). The ring counters are staged by the interconnections 32, 34, 35 and 38 so that each counter delivers to the next following one a single pulse when it reaches` a count' of ten, it being assumed in the present instance that the counters are. decade counters since it is desired to provide the results in a decimal system. It will become evident, without further discussion, that the counters and their associated parts may be arranged for price in non-decimal monetary systems- Associated with'thelast three ringcounters mayberexhibiting devices as indicated at tti indicative of; the total volumeof fuel delivered. For this purpose 42, teland 46 are respectively con necte'dto the three' fnalring'counter stages 20, 22 and 24. These indicators may be in the form of gas tubes conshow directly,rby glassglow, thepertinent digits. A decimal point 38 may be provided in the lform of a continuously glowing gas tube. This exhibition'of total fuel delivered may,

of course, be provided by mechanical counters coupled in conventional fashion to the ring counters.

The various output leads at 26, 28 and 30, one of each group corresponding to Aeachusigniicant digit in its ring counter, are connected to contact'points which may be selectively switched by means of switch elements 50, '52 and 54 which are connected to the common line 56. These switches are arrangedasdiagrammed, so that, for example in the case of switch 50, the lead corresponding lto 'the digit 1 in the ring counter maybe connected, or the two. leads corresponding to the.- digits 1 and l 2,A r`,or ,other series ranging from lv tothehighest digit forwhich seting -50 engages the leads correspondingv to digitsl and Zand, as will appear, has a setting corresponding` to a digit 2 in the tens place of' the price yper gallonI in cents. In similar fashion, the switchelementvSZ is in a position is desired.4 For example, as shown, the contact corresponding to sevenl cents. The switch element` 54 is r-f in arposition correspondingrto 0.9 cent. The total price per gallon'corresponding to the settings illustrated is 27.9

cents. Y

Pulses emitted from the common line 56`pass to the conventional decimal counter 53 which provides an output to a total price exhibiting means indicated at 60 and which may take one of the forms described above with reference to the quantity indicator 40. A decimal point is provided at 62 and the exhibited total price shown in tenth of 4a cent. t l

It will be evident from what has been described, that vvof the pulses entering the ring counter 1,6 two pulses out of every ten will be delivered to the line 56. Since FlGURE l is 3.152 dollars, the price being given to the i' .r

v'only every tenth pulse entering the ring counter 16 will v line 56 nine pulses for every thousand ventering the ring ,counter 16. It may be here noteduthat since the counter 16 does not emit a pulse to the line 56 when a pulse isdelivered to the counter 18, the same being true with respect to the counters 18 and 20, the several counters will never emit simultaneously any plurality of pulses to the line 56. There is thus no necessity for the pro- ,vision of any anti-coincidence arrangement of the type frequently used in other Yapparatus to avoid improper ,counting when pulses may be emitted simultaneously.

The theory of operation will now be given.

A number M is represented in the decimal scale as:

Its product with N, vwith inclusion of a decimal scale factor 10n+1 is then:

vl0V

11o 70"" +N'10n+1+N'10n+a+ Suppose, then, that .a quantity to be multiplied by -a second quantity M is measured by i Yadapted .to the different fashions in which fuel is de- .livered.

4 gallons of gasoline at M cents per gallon to be exhibited on a dispensing pump or on a panel associated with a pump. If pulses are generated by a meter at the rate, say, 1,000 pulses per gallon, l0n+1 may be 1,000. Suppose the price M is fixed to the tenth of a cent per gallon, say 27.94 cents, and the total price is to be given to the tenth of a cent. Then pn=2, p 1=7, pn 2=9 and the lsubsequent ps are zero. Assume in a particular delivery 'there are delivered 11.3 gallons. The total number of pulses then produced in the delivery will be 11,300.

Suppose, now, that provision is made for the deliveries of fractions of the total number of pulses corresponding ,to the fractions y Y I p ,lpvl 10102 Then the right hand:y side of the last equation becomes: 11,300-%+11,300f%00+1.1,300%00o which, tothe extent of the integral number ofpulses represented by each term is:

i If these pulses are counted on a decimal counter with ,the decimal point suitably assigned, the total price is given as $3.152, accurate to the tenth of a cent.

Considering, now, the application of the foregoing to a gasoline stationit will be recognized that at any usual .gasoline station the duty cycle of the computing apparatus is quite low; i.e., actual delivery of gasoline occupies only a small fraction of total time. YEven assum ing that the gasoline station has a large volume of business and to avoid delays in servicing it may require, for example, ten delivery stations provided with fuelhoses and nozzles, it Would be quite unlikely that more than four of these would actually beV delivering gasoline at any .one time. Even though more than four vehicles were present, sevices other than the actual delivery of gasoline would be involved for major por-tions of their stays. Thus, except for abnormal overload conditions it would suffice to have no more than four computing devices, certainly no more than the number of attendants present. It will be evident, therefore, that selective switching devices of quite obvious character may be provided vwhereby Vthe computing devices may be selectively con# `delivery unit and is available for price calculation. In-

dicators such as 40 and 60 may be provided individual to the delivery nozzles, these being involved in the selective switching. The entire system thusv involves saving of computing devices as well as much simplification of thegasoline station lay-out. The computers may be housed in the service building, and the vehicles may be routed for service into parallel areas each having asso ciated with it an overhead support for a delivery hose and nozzle and confronted with indicators such as 40 and 60 observable by the driver and the servicing attendant.

,The required land area for the gasoline stationmay thus b e reduced far below that which is presently conventional for an equivalent service capacity.V

The system which has been described is veryY readily Some customers will request filling of the tank. This may be automatically achievedY by interruption of the Vfilling by switching means when the tank is filled by the use, for example, of the arrangement described in the application of Shawhan, Serial No. 716,757, filed February 21, 19,58, now Patent No. 2,918,095, dated December '22; 1959. Y y v Other customers may request the delivery of a. certain.

number of gallons orv of a tween changes of digits of M.

Y'egos-11,031

quantity of fuel amounting to a certain` price. These later requirements may be satised by providing automatic stoppingV when the indicationof the ring counters 20, 22 and 2d or of the decilmal' counter 5S reach certain values; These provisions are not indicated in FIGURE l since, asV described below in FIGURE 3, there may be provided a device for interrupting operation under such conditions.

ln an operation such as that above described, the quantity M is a constant` throughout one operation. But that is not necessarily involved in the application of the present invent-ion whichl may be applied to the approximate evaluation ofY an integral or summation of the'v type fuma 'the summation over the integration interval of groups of pulses, each corresponding -to a small subperied be- It will be evident that the summation, approximating the integration, will -be statistical in nature with possible losses of pulses during transitions of the apparatus used; but with transition periods of minimum durations andl suitable high frequencies of pulses, the statistical approximation may be made extremely good.

FIGURE-2 illustrates an apparatus for performing the type of sum-mation or integration just mentioned. To.-

indieate the generality obtainable, FIGURE 2 illustrates an apparatus in which the input signals to be multiplied originate inthe form of variable voltages such as might be provided from any elec *ical analog. Further, the apparatus is shown as delivering a variable potential which may then be used as an input toan analog system.

A pulse generator 64 is ar-ranged to Ydeliver pulses at a constant suitably high frequency. This provides an inpu-t to a modulating system which controls the number of pulses emitted during a unit interval in proportion to an input voltage, the modulated pulse trainv becoming, then, Ithe'equivialent of such an inputv pulse train as is delivered from the anipliiier 14 in FIGURE 1 which involves the directy generation et pulses dat a rate proportional to a variable.

rthe ygenerator ed delivers its-pulses to a ringV counter de which forms the first of a series indicated at do, o8 and 7il which may be of any number desired for the problems involved and which correspond in their interconnections `and characteristics with the counters 1d toA 2.1i in FEGURE l. Asin the case of FIGURE l, the ring 'counters have output connections 72, 7d and '76 corresponding to the individual digits l to 9. (In a ease such as that being now specifically described it may not be of importance to have involved a decimal system, and it will be understood that any desired system may be empioyed.)

One of the variables to ybe multiplied is provided by the potential EX which is shown as introduced between input terminal 78 'and ground. The input is delivered to a cathode follower Sil.

A linear potentiometer 32 is Yconnected between a positive supply terminal and ground and has its mova-ble contact Sd driven through reduction gearing 86 by a reversible motor connected at 9d' to a reversing relay 92 arranged to change the direction of rotation of the motor-depending upon whether the potential at contact 84 is, higher or lower than the output potential of the cathode follower 8h. The motor Sti may be of alternating or direct current `type but desirably has a high rate of arms of which one is .illustrated'at 98,

-98 is electrically connected to a brush 'be emitted when the drive is l6 rotationin comparison with the movement imparted to the contact S4 for the'sakeof securing. high accuracy.

The motor shaft 94Lcarriesv a drum which issur'rounde'd by aifriction bandv 96 which carries apluralityr of switch others providing reversing switches: which are indicated at`120` and- 122 'and' which willrbe hereafter described but-are not' shown in the diagram as'connected 'to the friction band 96. The switch arm 93 operates through a limited range of motion between contacts. respectively connected to positive and negative supply terminals 100'and`1`d2. Theswitcharm 104 bearing on commutator segmentsltlmounted on theV shaft 94`and connected `together and to a line 108.

The operationof the matter just described is asfollows:

The operation of:` motor 88" under control cf thereversing relay 92'issuch as to Amaintain'equality between 'the potential at 84 andfthe potential attthecathodefofthe cathode follower Sti which is4 substantially proportional to the'input potential EX. (If'the maintenance of Va high degreeof equality is` desired, thev cathode-follower St). may, of course, be replacedbya circuit'arrangenient which will `maintain almost precisely equal the potential at84 and EX, such asV anV arrangement involving a high gain differential amplifier.) If the positionfof the contact 84 starts from ground, the total movement at any time will be reilected in the net positive pulses delivered at108 through the commutator and'brush arrangement, and the'. number of pulses thus delivered is proportional to the input potential. The arrangement of switch 98 is such that positive pulses will be emittedwhenthe motor rotates to drive the contact 84 in the positive direction and negativepulses will in the opposite direction. When the input voltage does not changethe net pulse count remains constant, and as will'immediately appear this maintains constant the switching set-upr which routes the pulses from the ringcounters.

The line ldd feeds its pulses to the first bidirectional ring counter'ltl ofa series indicated at 110, 112 and 114 corresponding individually to the ring counters but in reverse order. Each of these bidirectional ring counters is lof a type which will count upward on receipt cf positive pulses and downward on receipt of negative pulses. The rst ring counterlltlvreceivers the positive and negative pulses-:from the commutator 165 directly. The second counter 112 receivers its pulses through connection 116 when the-lirst ring counter passes through Zero, and to provide positive or negativevpulses depending upon the direction of change, there may be involved switching devices such as and' 122 which may be controlled bythe friction band 95, so, alternatively,.the introduction of positive or negative pulsesl maybe electrically/controlled in dependence uponwhether the zero of the counter llo is reached from -a count of-1` or from a'count of 9. The arrangement, in any. form, is' such thatthegroup of counters ill), liZ andfli willlallcount upward'or downward de pending upon theintroduction at 193 of positivefor negative pulses.

The respective bidirectional counters control switching of their corresponding ring counters 'of the group 65 to 7i? in the fashion which may b'ebestidescribed by considering the corresponding counters 66 and 114. Each ofthe outputterminals 72 ofv counter'is connected to an input terminalof-an and'gate 128. lThe other input terminal ofeachtof thesegates` isconnected to one of the digital outputs of thebidirectional counter 114 as indicated` at H4. klietwecn thesuccessive'connections 172.4 there are arranged the diodes 126. Assuming that as the lsuccessive. counts of counterlM are reached the output rrni'nals on'the side of the counter pulses to the line 130 :the ring counter 66;

.tionswhich the contact t) may assume, fact that the gates are electrically controlled there is no `limit to the rapidity of. change 'any'mechanicalconnectiona and the switching may ac- .cordingly follow rapid .potential Ex .motor 88 may .effect balancing at thepotentiometer 82.

`the gates associated with allof the ring counters kinput to the first ring counter 16 in curs in accordance with upon the If high accuracy Was not ing pulses at frequencyrates dependent upon a variable to be multiplied might provide the pulses on line 139, forY frequency outplied d'irectpote'ntials.

be provided to supply i 130. In suchv cases the right hand portion of FIGURE 2 wouldbe of interest to provide forirapid variation of Q switching-at rates in excess ofjthose which couldbe se- ,spendet 114 energized.' The gates are such that when so energized they will deliver whenever pulses are received from It will be evident, on comparing this action with that involving the switch 50 in FIGURE l, .that the gates 12S correspond in groups to the posibut due to the of switching imposed by changes in the valve of the input limited only by the rapidity with which the receives pulses from 66 to 7). It' should be here noted, to -avoid confusion, that It will be noted that .the line 130 .what has just been described is merely' a means for modrulating the pulsesin number in correspondence with the Ainput potential.

In a sense, multiplication is here involved, but it is with the quantity unity in view of the constant frequency of :pulses provided by the generator 64. The connection 130 is, essentially, equivalent to the FIGURE l.

At the right of FIGURE 2 the apparatus illustrated is identical with that at the nated by the same numerals primed. In the case of the right hand arrangement, the other of the variables to be multiplied Ey, is introduced between ground and the terminal 78. Between the input at 130 and the output at 132 there occurs precisely the same type of multiplying action as was described in connection with FIGURE l, the output connection 132 corresponding to 56 of FIG- URE l. Since the frequency of pulses introduced at 130 is proportional to the value of EX,v and since the switching corresponds to the instantaneous values of the input Ey, it will be evident that multiplication continuously octhe theory heretofore discussed with the result that a counter 134 receiving the input from line 132 accumulates (as an approximating summation) the value of the integral which is shown in FIGURE 2 applied to the terminal connected to the potentiometer contact 142. If a digital evaluation of this integral is desired, the apparatus may terminate with the counter 134. However, if it is desired to recover a potential Ez for use in further analog operations or for indication on a meter,

the output from the counter 134 may operate a digital motor drive indicated at 136 which in turn drives a digital motor 13S the shaft 140 of which adjusts a contact 142 on the potentiometer 144 connected between a positive supply terminal and ground. The digital motor drive 136 takes the same form as a bidirectional ring counter, and a Vsuitable circuit for effecting the results desired will be described hereafter with reference to FIGURE 4.

A potential corresponding to EZ might also be provided by applying to suitable summing resistors (through diodes blocking reverse current flows) potentials from the elements of the counter 134.

It may be noted that the apparatus shown in FIGURE 2 to the left of connection type of input which might replace Ex. For example, if the variable input was to be a measure of a ow, there could be used directly a variable frequency pulse input arrangement of the type shown in FIGURE l. required other systems generatexample, multivibrators are known with puts, through at least limited ranges, proportional to apv Such an arrangement might well the pulses introduced through line left and will, acordingly, not be vdescribed in detail, the corresponding parts being desig- 136 may be varied depending i -is adapted for first quadrant multiplaction, i.e.,

--cured through the mechanical switching arrangement of FIGURE 1.

The arrangement specifically illustrated in FIGURE 2 multiplication in which the introduced variables are of the same sign. It will be at once apparent that if the variables .have -both positive andnegative values provisions may be made for suitable switching-to provide an output which fat all times has a proper sign, these provisions providing positive and Anegative outputs at 132 delivered to a counter 134 which, in such case, would be bidirectional.

,The switching, of course, would be such that so long as y`EX and Eyhave the same sign, the output pulses would be positive while if they were of opposite signs the output pulses would be negative, the terms positive and negative being here .used in the sense of effects on the counter rather than in the sense of actually being positive or negative potentials with respect to ground.v The necessary switching arrangements will be obvious, certain of the ground connections in the system then being returned instead to supply terminals negative with respect to ground, as for example, the returns of the cathode A follower resistances and the right' hand terminals of the potentiometers 82 and S2.

The application of the invention to the process of division is illustrated in FIGURE 3. The arrangement here illustrated is in general similar to that illustrated in FIG- URE 1, though it will be obvious that the more elaborate arrangement of FIGURE 2 may be used. The process of -division consists, essentially, in multiplying a divisor by an input (which ultimately becomes the quotient) until the product acquires the value of the dividend. For this purpose, a pulse generator 150, which may be assumed to deliver positive pulses, provides its pulses through an or gate 152 to the first ring counter 154 of a group 154, 156, 158 corresponding to those shown in FIGURE 1. Any type of or gate 152 may be here used but it is exemplified as comprising parallel triodes capable indivtdually of` passing the positive pulses and shutting off the, supply of positive pulses to the ring counter 154' only when all three grids are driven to cut off by negative f potentials applied to lines 153.

The outputs of the ring counters are associated with the variable switches 162, 164 and 166 corresponding to the switches 50, 52 and 54. Indicators V16d connected toV the ring counters are arranged to exhibit the final digits composing the quotient. If the switches 162, 164 and 166 are arranged to correspond to the divisor, the counts represented by the input pulses are multiplied, effectively, by the divisor to provide a product output at 168. This ouput is delivered to the series of4 ring counters 17), 172, and 174 which have their outputs connected to the groups of terminals 176, 178 and 1?0 which are selectively engageable by the switch arms 182, 184 and 186 connected by the lines 153 to the grids of the gate tubes. The switches 182, 1S4'and 136 are setto correspond to the digits of the dividend. Assuming the outputs from the ring counters to be so chosen as to be negative, the negative outputs being suicient to cut off the triodes of the gate, it will be evident that pulses will be delivered from the generator until the product with the divisor reaches the value of the dividend whereupon all three of the triodes will be cnt off to stop the delivery of pulses. The

quotient will then be indicated att-160. Of course, any

`desired number of stages may be used to satisfy requirements.

The portion of FIGURE consisting of the ring Y counters 170, 172 and 174 andthe setting arrangements provided by the switch armsli, 184 and 186 are also illustrative of the fashion in which a gasoline dispensing computer such as that shown in FIGURE lmay termideenergization of l such as has been referred to heretofore the attainment-of predetermined' accumulationsv may control a gate suchas 152 to cause either energizationA or a relay to operate a valve to cut oit iiow of fuel. This procedure, of course,.is essentially one of division. For example, in the case of stoppage on attainment of a predetermined price, theV price is the dividend, theunit price is the. divisor, and the quantity of gasoline isv the quotient.

FIGUREA illustrates both a bidirectional ring counter and also a digital motor drive such as indicated at 136 in FIGURE 2. For simplicity of description, three stages are shown as would' be involved in a digital motorfdrive, but it will be obvious that the number-of stages maybe indefinitely increased to provide a decimalv counter or any. such other bidirectional counter as may be required.

Three triodes 19d, 192" and' 194 are connected in a circuit involving corresponding elements associated with eachtriode and similar interconnections which will be readily apparent frornthegure. There will be described thoseelements which are particularly associated' with the triode 19d.

Apositive supply terminal 1% is connected to the grid of triode190 through the resistor 198 and capacitor 200. The grid is also connected through a capacitor 262 and resistor 204 to the positive supply terminal 196 which is connected to the saine source as 196. The connections `to the succeeding triodes are the same between 196 and 196", between 196 and 96", etc.

A negative supply terminal 2015v is connected through resistor 26S to the grid of triode 190i. A diode 210 has itspositive terminal connected tothe junction ot4 resistor 198and capacitor 290, audits negativel terminal is connected through resistor 212 to vthe grid. of triode 190. A diode 214 has its positiveterrninal connected to the junction of resistor 264`v and capacitor 202 and' has its negative terminal connected to the grid of triode 19t) through resistor 216. A diode `218 has itspositive-terminal connected to the junction of resistor 198 and capacitor 290 and. its negative terminal tothe output terminal 229 of a bistable multivibrator 226. A diode 222 has its positive terminal connected to the junction of resistor 204 and capacitor 202 and has its negative terminal connected to the other output terminal 224 of the multivibrator 226. The input terminal-s 223 and 236 of the multivibrator 226 are so connected, as through the secondary of a transformer, that positive signals from a source such as the line Hi8 of FGURE 2 will provide a positive pulse at one of these terminals and a negative pulse at the other while a negative pulse will provide a reversal of these inputs. The bistable multivibrator is thus of a type that the rst positive input pulse will place itin one of its stable states and this state will be maintained so long a-s positive input pulses are received. On the other hand when a negative impulse is received the state wiil be reversed and will be maintained until a positive pulse is received. The control thus effected provides alternatively forward or reverse counting of the counter. The terminals 22d and 230 are connected to the negative terminals of diodes 232 and 234, the positive terminals of which are connected together and through line 236 to acapacitor 233 leading to the grid of triode 19d. The various connections to the triode 1% are repeated for the triodes 192 and i954 and such other ones as may be involved.

interconnections between the triodes are provided through the lines 24d and 242, it being noted that in the three stage arrangement shown the third stage is connected to the first as it to a subsequent stage. Each connection dit is between the anode of one stage to the grid of the next stage through a resistor corresponding to 212. Each connection 242 is from the anode of one stage through a resistance corresponding to 2id to the grid of the preceding stage.

The cathodes of the triodes are grounded, the ground phase windings and a lsubsequent triode conducting. Pulses li) being the reference for the positive and negative supply potentialsreterred to.

In the use of the lai-directional counter as a digital motor drive, the anode loads are constituted by the phase windings 244', 246 and 24g which are connected to the positive supply potential terminal 250. The digital motor is here considered to be of D C. type having the three field provided by a permanent magnet or by a D.C. winding connected between positive and negative supply terminals.

Resistors and potentials are so chosen that at any time only one ofthe triodes of the counters is conducting and hence only one of the phase windings is energized, positioning the rotor of the motor. When the bistable multivibrator is in a state so that the terminal 224 has a high positive potential compared to the terminal 220, successive negative pulses received through the line 236 from that terminal 228 or 2334 which is receiving negative pulses will be applied through the capacitors 238 to the grids of the triodes. A negative pulse applied to the triode which is conducting will cut oit this triode and render the next applied to the nonconducting triodes will be ineffective. Thus upon receipt of each pulse there will be a count in a forward direction in the counter. Ou the other hand, if the multivibrator terminal 220 has the high positive potential state, counting will take place in the reverse direction. A digital Imotor may thus be driven forwardly and backwardly step by step upon the receipt of each pulse. When the bidirectional counter is not used to operate a motor, positive or negative signals may be taken from suitable parts or" the counter. In such case, the anode loads may be constituted by resistors. The variations of connections for more stages than three will be obvious from the foregoing.

Bidirectional counters of other types may, of course, be employed, in connection with the invention.

What is claimed is:

1. InV combination, a plurality of individual ring-type recirculating counters each having therein a position corresponding to a full counting cycle; each individual coun- -ter having a plurality of output connections coupled directly to individual stages in the corresponding counter, the output connections thus providing individual output pulses from the several stages in the respective counters; connections from the said position of each individual counter save the last to the input of the next succeeding counter, thereby to sequentially stage the counters so that each individual counter save the last provides an input actuating pulse to its succeeding counter only upon completion of a full counting cycle; means providing input actuating pulses to only the first of said counters, a single common output terminal, and individual switching means comprising gates and ring counters controlling the states oi said gates, said individual switching means being singly associated with each respective one of the first-mentioned counters and operating to simultaneously connect selectively to said output terminal a plurality of said output connections of the individual inst-mentioned coun-ters.

2. A combination according to claim l, including also means for converting a continuously variable signal into corresponding pulses, and means delivering the last mentioned pulses to actuate said ring counters controlling the states of said gates.

3. in combination, a plurality of individual ring-type recirculating counters each having therein a position corresponding to a full counting cycle; each individual counter having a plurality or output connections the number of which is one less than the number of stages in the corresponding counter, said output connections being coupled directly to individual stages in the corresponding counter, the output connections thus providing individual output pulses from the several stages in the respective counters; connections from the said position of each inof which is one less than completion of a full counting cycle; means providing input vactuating pulses to only the `means operating to automatically modulate the frequency of occurrence of the last-named actuating pulses in ac- 4c ordance with a time-variable signal; a single common output terminal, and individual switching means singly associated with each respective counter and controllable to simultaneously connect selectively to said output terminal a plurality of said output connections of the individual counters.

4. In combination, a plurality of individual ring-type recirculating counters each having therein a position corresponding to a full counting cycle; each individual counter having a plurality of output connections the number of which is one less than the number of stages in the corresponding counter, said output connections being'coupled directly lto individual stages in the corresponding counter, the output connections thus providing individual output pulses from the several stages in the respective counters; connections from the said position of each in'- dividual counter save the last to the input of the next succeeding counter, thereby to sequentially stage the counters so that each individual counter vsave the last provides an input actuating pulse to its succeeding counter only upon completion of a full counting cycle; means providing input actuating pulses to only the first of said counters, a single common output terminal, individual switching means singly associated with each respective counter and controllable to simultaneously connect selectively to said output terminal a plurality of said output connections of the individual counters, and means automatically` controlling said switching means in accordance with the value of a time-Variable signal.

5. In combination, a plurality of individual ring-type recirculating counters each having therein a position corresponding to a full counting cycle; each individual counter having a plurality of output connections the number the number of stages in the iirst of said counters, said corresponding counter, said output connections being cou- Apled directly to individual stages in lthe corresponding counter, the output connections thus providing individual output pulses from the several stages in the respective counters; connections from the said position of each individual counter save the last to the input of the next succeeding counter, thereby to sequentially stage the counters so that each individual counter save the last provides an input actuating pulse to its succeeding counter only upon completion of a'full counting cycle; means providing input actua-ting pulses to only the first of said counters, a single common output terminal, and individual switching means singly as-sociated with each respective counter and' controllable to simultaneously connect selec- 15- tively to said output terminal a plurality of said output connections of the individual counters.

"References Cited in the tile of this patent UNITED STATES PATENTS Great Britain June 13, 1951 'OTHER REFERENCES y Slaughter: An Analog-To-Digital Converter With an i Improved Linear-Sweep Generator, Convention Record of March 23-26, 1953, IRE National Convention, Part 7 (April 1953),.pp. 7 to 12. v

Packer: Dynamic Binary Counter With Analog Read- Out, Convention Record of the March 23-26, 1953 IRE National Convention, Part 7 (April 1953), pp. 13-19. 40 Brierley: An Industrial Batclring Counter, Electronic Engineering (April 1954), vol. XXVI, No. 314, pp. 157 to 162. 

1. IN COMBINATION, A PLURALITY OF INDIVIDUAL RING-TYPE RECIRCULATING COUNTERS EACH HAVING THEREIN A POSITION CORRESPONDING TO A FULL COUNTING CYCLE; EACH INDIVIDUAL COUNTER HAVING A PLURALITY OF OUTPUT CONNECTIONS COUPLED DIRECTLY TO INDIVIDUAL STAGES IN THE CORRESPONDING COUNTER, THE OUTPUT CONNECTIONS THUS PROVIDING INDIVIDUAL OUTPUT PULSES FROM THE SEVERAL STAGES IN THE RESPECTIVE COUNTERS; CONNECTIONS FROM THE SAID POSITION OF EACH INDIVIDUAL COUNTER SAVE THE LAST TO THE INPUT OF THE NEXT SUCCEEDING COUNTER, THEREBY TO SEQUENTIALLY STAGE THE COUNTERS SO THAT EACH INDIVIDUAL COUNTER SAVE THE LAST PROVIDERS AN INPUT ACTUATING PULSE TO ITS SUCCEEDING COUNTER ONLY UPON COMPLETION OF A FULL COUNTING CYCLE; MEANS PROVIDING INPUT ACTUATING PULSES TO ONLY THE FIRST OF SAID COUNTERS, A SINGLE COMMON OUTPUT TERMINAL, AND INDIVIDUAL SWITCHING MEANS COMPRISING GATES AND RING COUNTERS CONTROLLING THE STATES OF SAID GATES, SAID INDIVIDUAL SWITCHING MEANS BEING SINGLY ASSOCIATED WITH EACH RESPECTIVE ONE OF THE FIRST-MENTIONED COUNTERS AND OPERATING TO SIMULTANEOUSLY CONNECT SELECTIVELY TO SAID OUTPUT TERMINAL A PLURALITY OF SAID OUTPUT CONNECTIONS OF THE INDIVIDUAL FIRST-MENTIONED COUNTERS. 